In a country where the national colour is green, the flag is partly green and the national teams' shirts are, yes, green, you might have thought the Green Party would have had a sniff of power before now.

Bertie Ahern has led coalition governments since 1997

The party is finally getting its chance, having signed up to be part of a coalition government for the next five years.

Governing by coalition is pretty much the norm in Ireland. But for the Greens, it is a huge step. And for Irish politics, it marks a significant moment.

Ireland's Greens, as in other European countries, have smartened up their act in recent years, swapping the muesli and sandals image for something more serious.

In Irish politics, election day is only the start of the fun.

Next comes the vote-counting, which under the system of proportional representation used here can take days.

Then comes the horse-trading over the formation of a government.

Third-term taioseach

For the past couple of weeks, the politicians involved have looked increasingly weary, as the marathon talks to reach an agreement have stretched on.

When Ireland voted on 24 May, Bertie Ahern's Fianna Fail party won 78 of the 166 seats in the Dail, the Irish parliament.

An unexpectedly strong return, but not enough for an outright majority.

It is the prospect of the Greens in government that is most exciting the political commentators here

So Mr Ahern, who has been in power since 1997, needs partners as he embarks on his third term as taioseach, or prime minister.

Popular and affable, he is also a wily and seasoned negotiator. And, like his party, he is pragmatic.

Over the past decade, he has worked in tandem with the right-of-centre Progressive Democrats.

The PDs, as they are known, have shrunk to just two members of parliament, but will still be back in government, along with a small group of independents, with whom Mr Ahern has thrashed out attractive deals to keep voters in their constituencies happy.

High price

It is the prospect of the Greens in government that is most exciting the political commentators here, however.

The irony is that gaining seats at the cabinet table will follow what was a pretty disappointing election result for the party.

They lost one prominent figure and gained another, so retained six seats.

Mr Sargent resigned rather than go into coalition with Fianna Fail

Since then, though, senior figures have been in exhausting talks with Fianna Fail.

An agreement was reached, and after an emotional internal debate at a special convention held in Dublin, Green Party members gave their assent to go into government.

Signing up has meant the Greens have had to leave some of their key objectives at the front door.

A commitment was won to introduce a carbon tax and to set targets for the reduction of 3% of greenhouse gas emissions a year.

There will be a commission to look at the financing of the political system.

But the US military can still use Shannon airport in the west of Ireland, a controversial motorway plan north of Dublin will go ahead, and a new hospital-building policy opposed by the Greens will still happen.

For some in the party, this was too high a price to pay for gaining a hand on the reins of power.

Perhaps strangest of all was the sight of the Green Party leader, Trevor Sargent, hailing the proudest day of his life as the Greens voted to go into government, and then promptly resigning.

Mr Sargent had pledged before the election that he would step down rather than go into power with Fianna Fail.

Mr Ahern can head off on his holidays a satisfied man.

Lauded for his part in the process which returned devolved government to Northern Ireland, he endured a challenging election campaign and defied a few pundits to return to office.

His friend and partner in the Northern Ireland process, UK Prime Minister Tony Blair, is about to leave the stage.

For his part, Mr Ahern is about to see how the new, greener tinge to Irish politics works out.